Why can one switch view neighbor information but cannot the other switch view neighbor information after the two S series switches establish RIP neighbor relationship

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Q: Why can one switch view neighbor information but cannot the other switch view neighbor information after the two switches establish RIP neighbor relationship?

A: A switch enabled with RIP does not send the route of the interface directly connected to the neighbor. If both ends only have direct routes, only one switch can discover the neighbor.
For example, before device A and device B establish RIP neighbor relationship, if device A sends the interface route to device B, device B will discover device A. Device B then does not advertise its interface route to device A. Consequently, device A cannot discover the neighbor device B. RIP does not stipulate that whether a switch needs to send the route of the interface directly connected to the neighbor to the neighbor.
This issue occurs when Huawei's communications products establish RIP neighbor relationship.

Other related questions:
Check OSPF neighbor information on S series switches
You can run the display ospf peer command on an S series switch with OSPF configured to check whether the OSPF neighbor status is normal. For example: [HUAWEI] display ospf peer OSPF Process 1 with Router ID 10.1.1.2 Neighbors Area 0.0.0.0 interface 10.1.1.2(Vlanif100)'s neighbors Router ID: 10.1.1.1 Address: 10.1.1.1 GR State: Normal GR State: Normal State: Full Mode:Nbr is Slave Priority: 1 DR: 10.1.1.2 BDR: 10.1.1.1 MTU: 0 Dead timer due in 35 sec Retrans timer interval: 5 Neighbor is up for 00:00:05 Authentication Sequence: [ 0 ] Note: If Full is displayed in State, LSDB synchronization has been completed and the two switches have set up the full adjacency relationship.

Can an OSPF neighbor relationship be established if the network types of the two S series switches are different
Question: Can a Full neighbor relationship be established if the network types of the two ends of an OSPF link are different? Answer: Yes. For example, two devices are interconnected through an Ethernet link. On one end of the link, the default broadcast network type is adopted. The other end is configured as OSPF peer-to-peer (P2P). Neighbor relationship can be established between these two devices, which reach the Full state by exchanging their Link State Databases (LSDBs). However, no route can be learned because OSPF devices need LSDBs to construct a Shortest Path Tree (SPT). The LSDBs, however, are problematic. That is, the link-state advertisements (LSAs) generated by one end consider the peer a broadcast neighbor, while the other end considers its peer a P2P neighbor. Therefore, no SPT can be constructed correctly and the Shortest Path First (SPF) algorithm cannot calculate the right routes either.

Why can IS-IS neighbors not be established
This has the following possible causes: -Point-to-multipoint (P2MP) interfaces do not support the Intermediate System to Intermediate System routing protocol (IS-IS). -The MTU of the Ethernet Interface is smaller than the max-size of IS-IS LSP packets plus 3. -The MTU of the point-to-point (P2P) interface is less than the length of the IS-IS LSP packet. -The two ends have different parameter configurations.

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